View source for Engineering:Texas Instruments TMS1000

[[File:TI TMS1000NP 1.jpg|thumb|right|A TMS1000 "computer on a chip". The date code on this part shows it was made in 1979.  It is in a 28-pin plastic dual-in-line package.]]
[[File:Tms1100-merlin.png|thumb|Texas Instruments TMS1100 microcontroller inside the Parker Brothers Merlin electronics game.]]
The '''TMS1000''' is a family of [[Engineering:Microcontroller|microcontroller]]s introduced by [[Company:Texas Instruments|Texas Instruments]] in 1974.<ref>{{cite web |author=Texas Instruments |title=Texas Instruments History 1970's |url=http://www.ti.com/corp/docs/company/history/1970s.shtml |url-status=dead |archiveurl=https://web.archive.org/web/20060118040459/http://www.ti.com/corp/docs/company/history/1970s.shtml |archivedate=18 January 2006 |date=2006 |quote=1974: Introduces TMS1000 one-chip microcomputer. }}</ref><ref>{{cite web |author=Texas Instruments |title=TMS 1000 One-Chip Microcomputers |url=http://www.ti.com/corp/docs/company/history/tms.shtml |url-status=dead |archiveurl=https://web.archive.org/web/20050213130208/http://www.ti.com/corp/docs/company/history/tms.shtml |archivedate=13 February 2005 |date=2005 }} This is Texas Instruments' original 1974 announcement of the TMS1000 family.</ref><ref>{{cite book |editor1-last=Siewiorek |editor1-first=Daniel P. |editor2-last=Bell |editor2-first=C. Gordon |editor3-last=Newell |editor3-first=Allen |title=Computer Structures: Principles and Examples |date=1982 |publisher=McGraw-Hill |isbn=0-07-057302-6 |page=[https://archive.org/details/computerstructur01siew/page/583 583] |chapter-url=https://archive.org/details/computerstructur01siew |accessdate=8 November 2017 |chapter=Part 3: Computer Classes, Section 1: Monolithic Microcomputers |quote=The TMS1000 was introduced in 1974 and used in the SR-16 calculator. |chapter-url-access=registration |url=https://archive.org/details/computerstructur01siew/page/583 }}
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It combined a 4-bit central processor unit, read-only memory (ROM), random access memory (RAM), and input/output (I/O) lines as a complete "computer on a chip". It was intended for [[Embedded system|embedded system]]s in automobiles, appliances, games, and measurement instruments.

It was the first high-volume commercial microcontroller.  In 1974, chips in this family could be purchased in volume for around $2 each.<ref name=RZ09/>  By 1979 about 26 million parts in this family were sold every year.<ref>{{cite book |first1=David L. |last1=Morton Jr. |first2=Joseph |last2=Gabriel |title=Electronics: The Life Story of a Technology |publisher=JHU Press |year=2007 |isbn=0801887739 |pages=113 }}
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The TMS 1000 was used in Texas Instruments' own ''Speak & Spell'' educational toy,<ref name=RZ09>{{cite book |first=Richard |last=Zurawski |title=Embedded Systems Handbook: Embedded Systems Design and Verification |publisher=CRC Press |edition=2nd |year=2009 |isbn=1439807639 |pages=12–13 }}</ref> the [[Engineering:Big Trak|Big Trak]] programmable toy vehicle and in the electronic game [[Software:Simon (game)|Simon]].<ref>{{cite book |first1=Michael |last1=Austin |chapter=Ch. 1 |title=Music Video Games: Performance, Politics, and Play |publisher=Bloomsbury Publishing |year=2016  |isbn=1501308505 }}</ref>

==History==
=== TMS 0100 series ===
The Smithsonian Institution says [[Company:Texas Instruments|TI]] engineers Gary Boone and Michael Cochran succeeded in creating the first microcontroller (also called a microcomputer) in 1971. The TMS1802NC was a single-chip microcontroller which was announced September 17, 1971 and implemented a four-function calculator. The TMS1802NC, despite its designation, was not part of the TMS 1000 series; it was later redesignated as part of the TMS 0100 series, which was used in the TI Datamath calculator and the Sinclair Executive calculator.<ref>
[http://www.vintagecalculators.com/html/the_calculator-on-a-chip.html "The Arrival of the "Calculator-on-a-Chip"].
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=== TMS 1000 series ===
[[File:TI TMS1000C die.jpg|thumb|The die of a TMS1000C]]
The later TMS 1000 series went on the market in 1974. TI stressed the 4-bit TMS 1000 for use in pre-programmed embedded applications.<ref>{{cite book |first1=Frederick |last1=Seitz |first2=Norman G. |last2=Einspruch |title=Electronic Genie: The Tangled History of Silicon |publisher=University of Illinois Press |year=1998 |isbn=0252023838 |pages=229 |url=https://books.google.com/books?id=IT90cDPh54wC&pg=PA229}}
[https://books.google.com/books?id=IT90cDPh54wC&pg=PA229 "Electronic Genie: The Tangled History of Silicon"], Frederick Seitz, Norman G.. Einspruch, University of Illinois </ref><ref>U.S. Patent no. 4,074,351 (TMS1802NC.)</ref><ref>{{cite journal |url=https://spectrum.ieee.org/tech-history/silicon-revolution/the-surprising-story-of-the-first-microprocessors |title=The Surprising Story of the First Microprocessors |first1=Ken |last1=Shirriff |date=August 30, 2016 |journal=IEEE Spectrum}}</ref><ref>{{cite book|title=The Most Widely Used Computer on a Chip: The TMS 1000|work=State of the Art: A Photographic History of the Integrated Circuit|last=Augarten|first=Stan|publisher=Ticknor & Fields|location=New Haven and New York|year=1983|isbn=0-89919-195-9|url=http://smithsonianchips.si.edu/augarten/p38.htm|accessdate=2009-12-23|url-status=live|archiveurl=https://web.archive.org/web/20100217065617/http://smithsonianchips.si.edu/augarten/p38.htm|archivedate=2010-02-17}}</ref><ref>{{cite press |url=https://web.archive.org/web/20060218021723/http://www.ti.com/corp/docs/company/history/calcchip.shtml |title=STANDARD CALCULATOR ON A CHIP ANNOUNCED BY TEXAS INSTRUMENTS |publisher=Texas Instruments |date=September 19, 1971}}</ref>

A computer-on-a-chip combines the microprocessor core (CPU), memory, and I/O ([[Input output|input/output]]) lines onto one [[Engineering:Integrated circuit|chip]]. The computer-on-a-chip patent, called the "microcomputer patent" at the time, {{US patent|4074351}}, was awarded to Gary Boone and Michael J. Cochran of TI. Aside from this patent, the standard meaning of [[Microcomputer|microcomputer]] is a computer using one or more microprocessors as its CPU(s), while the concept defined in the patent is more akin to a microcontroller.

==Description==
The TMS1000 family eventually included variants in both the original [[PMOS logic|PMOS]] logic and also in [[NMOS logic|NMOS]] and [[Engineering:CMOS|CMOS]]. Product variations included different sizes of ROM and RAM, different I/O counts, and ROMless versions intended for development or for use with external ROM. The original TMS1000 had 1024 x 8 bits of ROM, 64 x 4 bits of RAM, and 23 input/output lines.

The TMS1000 family used [[Mask ROM|mask-programmed ROM]]. Once the user had a debugged program ready to be committed to production, it would send the program to Texas Instruments who would then make a special mask to program the on-chip ROM. The ROM could not be altered in the field; the contents were fixed by the patterns laid down on the chip by the manufacturer. While this process had a high initial cost, the production cost was very low, making it suitable for high volume products (say, more than a few thousand items sold per year).

All internal data paths of the processor were 4 bits wide. Program ROM and data RAM were separately addressed as in a [[Harvard architecture]]; this became a typical characteristic of microcontrollers by many other manufacturers.

The [[Arithmetic logic unit|ALU]] had a carry flag to indicate overflow and facilitate multiple precision arithmetic. On-chip RAM was addressed by X and Y registers, where X had 4 bits and Y had either 2 or 3 bits depending on the size of RAM on the part. The program counter was 6 bits wide, with "page" and "chapter" registers to address up to 2&nbsp;KB of ROM program memory.

No stack was provided, but a register was provided to store the program counter and carry flag to allow for one level of subroutine (some members of the family allowed for 2 or 3 levels). No interrupt facility was provided.

Some models had as few as 4 I/O lines because they had no on-chip ROM and the limited number of package pins were needed to access off-chip program memory. One version had special outputs for driving a [[Engineering:Vacuum fluorescent display|vacuum fluorescent display]], and a [[Programmable logic array|programmable logic array]] useful for driving seven segment displays. Four input lines were provided for purposes such as sensing keyboard inputs, and a varying number of output lines were provided to control external devices, or to scan the rows of a keyboard.

PMOS versions ran on -9 or -15 volts and consumed around 6 mA, Output logic levels were therefore not compatible with TTL logic. The NMOS and CMOS parts ran on a TTL-style +5 volts and could interoperate with 5 volt logic.

Instruction sets varied slightly by model, with 43 instructions in the basic set and 54 available in some family members; instructions were 8 bits long. [[Binary-coded decimal|BCD]] arithmetic instructions were provided, but no instructions were available for logical AND or OR of registers. [[Subroutine]]s were limited to 1 level in some parts (a subroutine could not call another subroutine), with 2 or 3 levels available on others.

Each instruction took between 10 and 15 microseconds to execute on the NMOS and PMOS parts, but some CMOS parts could be run as fast as 6 microseconds. The internal oscillator gave an effective clock speed of around 0.3 megahertz.

The TMS1000 parts were packaged in through-hole [[Engineering:Dual in-line package|dual in-line package]]s with 28 or 40 pins, but some models for prototyping were in 64-pin packages. All versions had a temperature range of 0 to 70 degrees C.

Since these were intended as single-chip embedded systems, no special support chips UARTs, etc. were specifically made in the TMS 1000 family.<ref>{{cite book |first1=S. A. |last1=Money |title=Microprocessor Data Book |edition=2nd |publisher=Academic Press |year=2014 |isbn=1483268705 |pages=35–37 }}</ref>

==References==
<references/>

==Further reading==
{{refbegin}}
*{{cite book|author=The Engineering Staff of Texas Instruments Incorporated, Semiconductor Group|title=TMS 1000 Series MOS/LSI One-Chip Microcomputers|date=1975|url=http://bitsavers.informatik.uni-stuttgart.de/components/ti/TMS1000/TMS_1000_Series_MOS_LSI_One-Chip_Microcomputers_1975.pdf}}
*{{cite book |author-mask=1|author=The Engineering Staff of Texas Instruments Incorporated, Semiconductor Group|title=TMS 1000 Series MOS/LSI One-Chip Microcomputers: Programmer's Reference Manual|date=1975|url=http://bitsavers.informatik.uni-stuttgart.de/components/ti/TMS1000/TMS1000pgmRef_1975.pdf}}
*{{cite book|author-mask=1|author=The Engineering Staff of Texas Instruments Incorporated, Semiconductor Group|title=TMS 1000 Series Data Manual|date=December 1976|url=https://en.wikichip.org/w/images/9/91/TMS_1000_Series_Data_Manual_Dec76.pdf}}
*{{cite web |first1=Ken |last1=Shirriff  |title=Reverse engineering RAM storage in early Texas Instruments calculator chips |date=November 2020 |url=http://www.righto.com/2020/11/reverse-engineering-ram-storage-in.html}}
*{{cite web|author=OpenCores|title=Verilog implementation of the TMS1000 chip|date=August 2021|url=https://opencores.org/projects/tms1000}}
{{refend}}

{{Microcontrollers}}

[[Category:Microcontrollers]]

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